1. Field of the Invention
The present invention relates to the field of video image processing and display systems.
2. Description of Related Art
Video processing systems provide means for decomposing a video image into component portions. This decomposition process is particularly important for the transmission of a video image across a data network, such as a video teleconferencing network. In any given video image, some component portions of the image are more dynamic than others. For example, in a typical desktop video teleconferencing application, a moving or rapidly changing foreground image is often shown on an unchanging or static background image portion. It is advantageous to identify and individually process dynamically changing image portions independently from static portions of the image. This is particularly advantageous for updating a video image across a data network.
Prior art implementations employ a technique called chroma-keying. Chroma-keying involves identifying an image component based on a particular pre-defined chroma value. Pixels containing this chroma value are either replaced with an alternate static image portion or used to suppress the transfer of corresponding pixel data across a data network. These systems are limited by the pre-defined fixed chroma-key value.
In other network based video teleconferencing applications, the video source, such as a camera that supplies the image is typically of a higher resolution than the display device on which the image is displayed or the data network over which the image is transferred. In these applications, images are typically reduced in size prior to a process of image compression and thereafter enlarged after a process of decompression. The resulting image looses picture information and the processing of the image consumes substantial processor resources.
Thus, a better system for processing images is required.